Skip to main content
Log in

New approaches to selective pulse design

  • Invited Papers
  • Published:
Magnetic Resonance Materials in Physics, Biology and Medicine Aims and scope Submit manuscript

Abstract

Selective pulse design for noninteracting spins is equivalent to inversion of the Bloch equations. Until recently, few analytical solutions to this problem were known. However, approaches based on inverse-scattering theory have now led to general solutions that offer ever higher precision in meeting target responses. The concept of soliton pulses (pulses that leave the spin system unaffected) turns out to be a particularly valuable one because half-solitons (both π/2 and π pulses) are inherently phase compensated. Such pulses are important for observation of shortT 2 species, where substantial signal loss could occur in any refocusing period. Multiply-selective pulses, suitable for simultaneous suppression of several “solvent” lines have been generated by inverse-scattering theory and have considerable potential in bothin vivo magnetic resonance spectroscopy and in routine high-resolution NMR. Although analytical solutions show great promise, it is likely that optimization methods will continue to be of value for the foreseeable future. The use of the SPINCALC scheme that operates in a switched stationary reference frame is illustrated through its use to design adiabatic refocusing pulses that do not lead to cumulative errors when used in multiple-echo trains.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Institutional subscriptions

Similar content being viewed by others

References

  1. Garroway AN, Grannell PK, Mansfield P (1974) Image formation in NMR by a selective irradiative process. J Phys C7 L457-L462.

    Google Scholar 

  2. Morris PG, Mclntyre DJO, Rourke DE, Ngo JT (1986) Rational approaches to the design of NMR selective pulses.NMR Biomed 5/6 257–266.

    Google Scholar 

  3. Conolly S, Macovski A (1985) Selective pulse design via optimal control theory. Proceedings of the 4th Annual Meeting, Society of Magnetic Resonance in Medicare p. 958.

  4. Lent AH , Kritzer MR (1985) A new rf pulse shape for narrowband inversion: the WOW-180.Proceedings of the 4th Annual Meeting, Society of Magnetic Resonance in Medicine p. 1015.

  5. Kirkpatrick S, Gelatt CD, Vecchi MP (1983) Optimization by simulated annealing.Science 220 671–680.

    Google Scholar 

  6. Rourke DE, Mclntyre DJO, Morris PG (1989) A simulated annealing approach to the design of phase-compensated selective pulses.Proceedings of the 8th Annual Meeting, Society of Magnetic Resonance in Medicine p. 863.

  7. Geen H, Wimperis S, Freeman R (1989) Band-selective pulses without phase distortion. A simulated annealing approach.J Magn Reson 85 620–627.

    Google Scholar 

  8. Hardy CJ, Bottomley PA, O'Donnell M, Roemer P (1988) Optimization of two-dimensional spatially selective NMR pulses by simulated annealing.J Magn Reson 77 233–250.

    Google Scholar 

  9. Wu X-L, Xu P, Freeman R (1991) Delayed-focus pulses for magnetic resonance imaging: an evolutionary approach.Magn Reson Med 20 165–170.

    PubMed  Google Scholar 

  10. Ngo JT, Morris PG (1986) A new method for the optimization of NMR selective pulses.Biochem Soc Trans 14 1271–1272.

    Google Scholar 

  11. Ngo JT, Morris PG (1987) General solution to the NMR excitation problem for noninteracting spins.Magn Reson Med 5 217–237.

    PubMed  Google Scholar 

  12. Ngo JT, Morris PG (1986) Selective excitation: something for nothing.TAMU Newsletter 337 38–39.

    Google Scholar 

  13. Baum J, Tycko R, Pines A (1983) Broadband population inversion by phase-modulated pulses.J Chem Phys 79 4643–4644.

    Google Scholar 

  14. Silver MS, Joseph RI, Chen C-N, Sank VJ, Hoult DI (1984)Nature 310 681–683.

    PubMed  Google Scholar 

  15. Shinnar M, Eleff SM, Subramanian VH, Leigh JS (1989) The synthesis of pulse sequences yielding arbitrary magnetization vectors.Magn Reson Med 12 74–80.

    PubMed  Google Scholar 

  16. Buonocore MH (1993) RF pulse design using the inverse scattering transform.Magn Reson Med 29 470–477.

    PubMed  Google Scholar 

  17. Rourke DE, Morris PG (1992) The inverse scattering transform and its use in the exact inversion of the Bloch equation for non-interacting spins.J Magn Reson 99 118–138.

    Google Scholar 

  18. Rourke DE, Morris PG (1992) Half solitons as solutions to the Zakharov-Shabat eigenvalue problem for rational reflection coefficient with application in the design of selective pulses in nuclear magnetic resonance.Phys Rev A 46 3631–3636.

    PubMed  Google Scholar 

  19. Rourke DE, Prior MJW, Morris PG, Lohman JAB (1994) Stereographic method of exactly calculating selective pulses.J Magn Reson A 107 203–214.

    Google Scholar 

Download references

Author information

Authors and Affiliations

Authors

Rights and permissions

Reprints and permissions

About this article

Cite this article

Morris, P.G., Rourke, D.E., Intyre, D.J.O. et al. New approaches to selective pulse design. MAGMA 2, 279–283 (1994). https://doi.org/10.1007/BF01705253

Download citation

  • Issue Date:

  • DOI: https://doi.org/10.1007/BF01705253

Keywords

Navigation